Gas-phase cluster cations generated by direct laser ablation on AgBr/S mixture

The clusters produced by direct laser ablation on the sample made of mixtures of silver bromide and sulfur powder in different molar ratios have been studied with a home-built tandem time-of-flight mass spectrometer. The results showed that Ag3S+ was still formed even if the content of AgBr was very high in the samples (AgBr:S = 100:5). Additionally, the clusters, the general formula of which is AgmSp+ (m = 1-3, p = 1-5), were formed, predominantly AgS4+. The above binary clusters could combine AgBr units to produce ternary clusters. This work provided a further experimental proof for the argument proposed by the present authors that Ag3S+ and the analogs are deep photoelectron traps of photosensitive silver halide emulsion during the exposure process.